The present invention relates to a data recording/reproducing apparatus using a DVD(Digital Versatile Disk)-RAM and the like as a record medium, a data recording/reproducing method applied to the apparatus, and a computer program product used in a data processing apparatus. More particularly, the invention relates to a data recording/reproducing apparatus using a single record medium to handle audio/visual data such as DVD video and normal digital data used in a computer.
This application is based on Japanese Patent Applications No. 9-312344 filed on Nov. 13, 1997 and No. 9-329207 filed on Nov. 28, 1997, the contents of which are incorporated herein by reference.
In recent years, with progress of computer and multimedia, various multimedia-capable computer systems have been developed. Function for reproducing animation or sound data in addition to function for reproducing text data or graphic data is provided with such computer.
With such progress in multimedia of the computer, a DVD has lately drawn attention as a new record media taking the place of CD-ROM. One side of a single DVD-ROM media can store data of about 4.7 G bites which is about seven times volume of the current CD-ROM, and both sides of the DVD-ROM media can store data of about 9.4 G bites. By using the DVD-ROM media, it is possible to reproduce animation such as movie including a great amount of picture information on a computer at high quality.
On the other hand, development of a DVD-RAM medium which can read out and write in data has also been developed recently. Since the DVD-RAM medium is a medium having a large volume and capable of being written, the DVD-RAM medium is not only used for recording the animation data, but is also greatly expected as a secondary storing device of a computer. Further, the DVD-RAM medium has drawn attention as a new record media taking the place of a video cassette in public equipment such as a video camera or video tape player.
Therefore, the DVD-RAM can handle both audio visual data (which is referred to as AV data hereinafter) which regard actual time property as most important, and digital data (which is referred to as D data hereinafter) which regard accuracy as most important such as file data used in the computer.
However, when there is a defective sector during recording into the DVD-RAM medium, handling of the defective sector differs between AV data and D data. That is, in the case of AV data which regards actual time property as most important, it is preferable to keep recording even if the fact that data can not be recorded accurately in such a defective sector is ignored. On the other hand, in the case of D data, it is important to rewrite the D data in an alternative sector while regarding the accuracy as most important.
In general, an apparatus for recording/reproducing D data carries out, in recording processing of data, the verifying processing for checking whether the data has been correctly recorded after recording. Further, in reproducing processing of data, retry processing is carried out when a defect is generated. Since the D data is program data or file data made by various kinds of application software, if a defect is generated, the entire program may not be executed. Therefore, the verifying processing and the retry processing which is performed when a defect is generated are necessary and indispensable since reliability is regarded as most important.
Whereas, the AV data comprise image data or sound data, and it is important that the data are recorded and reproduced without interruption. Even if a defect is generated when the data are recorded or reproduced, this does not make it impossible to reproduce the AV data although a noise is generated in a portion of the picture. Therefore, AV data do not necessarily require the verifying processing or the retry processing.
As described above, a degree of necessity of the verifying processing or the retry processing differs depending upon the kind of data. However, conventionally, the verifying processing is carried out when data are recorded, and the retry processing is carried out when data are produced irrespective of kinds of data. Therefore, regarding a method for recording and reproducing D data, when image data having a great amount of data are recorded, extra time for verifying processing is required. Further, when the image data are reproduced, if the retry processing is carried out, the image which is in reproducing is interrupted for a time during the retrying.